Chemical analysis methods provide the user with an ability to determine the chemical make-up of a substance and thereby identify that substance. These methods have been used throughout various disciplines including forensics and security investigations. Today security requires a constant vigil and there is an increasing need for readily available, analytical procedures for evaluating the chemical make-up of potentially harmful or destructive materials. This need is more pronounced at airports and border crossings where a large number of parcels are examined over a large area in a relatively short period of time. One especially robust means of performing chemical analysis is mass spectrometry.
Mass spectroscopy is an analytical procedure for the separation and quantification of ions based upon the mass-to-charge ratio of the ions within a chemical sample. Traditionally, these instruments have been relatively large and non-mobile due to the operational requirements of the instrument, namely the large vacuum pumps to provide low pressures for ion currents, as well as high-voltage power generators, amplifiers, and matching circuits.
The chemical analysis procedures presently used in airport and border security include canines and ion mobility spectrometry (IMS). However, the ion resolution of IMS is far inferior to the commercially available mass spectroscopy unit. Thus, there is a need to implement the benefits of a mass spectrometer into the size of an IMS to further enable field research and environmental monitoring, including but not limited to, homeland security and defense applications.
A portable mass spectrometer would ideally be self-contained, operate at near atmospheric pressures with low electrical current demand, have a robust and flexible ion source, provide high resolution spectra with low signal-to-noise ratios, provide data interpretation, and be low cost.